Method for forming three-dimensional anchoring structures on a surface by propagating energy through a multi-core fiber

Abstract

A method for forming three-dimensional anchoring structures on a surface is provided. This method may result in a thermal barrier coating system exhibiting enhanced adherence for its constituent coatings. The method involves applying a first laser beam ( 20 ) through a first portion ( 7 ) of a multi-core fiber ( 4 ) to a surface ( 12 ) of a solid material ( 14 ) to form a liquefied bed ( 16 ) on the surface ( 12 ) of the solid material ( 14 ), then applying a pulse of laser energy ( 24 ) through a second portion ( 6 ) of the multi-core fiber ( 4 ) to a portion of the liquefied bed ( 16 ) to cause a disturbance, such as a splash ( 28 ) of liquefied material outside the liquefied bed ( 16 ). A three-dimensional anchoring structure ( 30 ) may thus be formed on the surface ( 12 ) upon solidification of the splash ( 28 ) of the liquefied material.

The invention claimed is: 
     
       1. A method comprising:
 propagating, via a first laser beam, a first laser energy through a first fiber of a multi-core fiber; 
 propagating, via a non-laser energy source a second non-laser energy selected from one of a mechanical energy, sonic energy, and ultrasonic energy within a hollow second fiber of the multi-core fiber; 
 applying the first laser energy to a surface of a substrate to form a liquefied bed on the surface; 
 applying the second non-laser energy to at least a portion of the liquefied bed to cause a splash of liquefied material outside the liquefied bed; and 
 forming on or above the surface of the substrate a three-dimensional anchoring structure upon solidification of the splash of liquefied material. 
 
     
     
       2. The method of  claim 1 , wherein the three-dimensional anchoring structure comprises at least one of a hook, a finger and a wave. 
     
     
       3. The method of  claim 1 , wherein the steps of applying the first laser energy comprises scanning the first laser beams relative to the surface of the substrate. 
     
     
       4. The method of  claim 1 , wherein the step of applying the second non-laser energy is performed during the step of applying the first laser energy. 
     
     
       5. The method of  claim 1 , wherein the first laser energy is continuous laser or pulsed. 
     
     
       6. The method of  claim 1 , further comprising providing one of an inert gas, a reactive gas, or vacuum conditions surrounding the surface during the applying steps. 
     
     
       7. The method of  claim 1 , further comprising applying a flux to the surface prior to the step of applying the first laser energy to the surface. 
     
     
       8. The method of  claim 1 , wherein the second energy is a mechanical energy comprising a burst of air. 
     
     
       9. The method of  claim 1 , wherein the second energy is a mechanical energy comprising a solid object having a size less than a diameter of the hollow second fiber. 
     
     
       10. The method of  claim 9 , wherein the solid object is a wire. 
     
     
       11. The method of  claim 1 , wherein the first laser energy is controlled to cause melting of the surface to a selected depth. 
     
     
       12. The method of  claim 1 , wherein the substrate comprises a gas turbine vane or blade, and wherein the method further comprises forming the anchoring structure in a bond coating layer or a ceramic thermal barrier coating layer of the substrate. 
     
     
       13. A method comprising:
 applying laser energy, via a laser energy beam, through an annular region of a multi core fiber to a surface of a solid material to form a liquefied bed on the surface of the solid material; 
 applying a pulse of non-laser energy, via a non-laser energy source selected from one of a mechanical, sonic, and ultrasonic energy, within a hollow inner core region of the multi-core fiber to cause a disruption in at least a portion of the liquefied bed; and 
 allowing the disruption to solidify on the surface of the solid material to form an anchoring structure. 
 
     
     
       14. The method of  claim 13 , wherein the anchoring structure comprises at least one of a hook, a finger and a wave. 
     
     
       15. The method of  claim 13 , wherein the laser energy beam is continuous or pulsed, and the disruption comprises a splash of liquefied material outside the liquefied bed. 
     
     
       16. The method of  claim 13 , wherein the non-laser energy source is mechanical and the pulse of non-laser energy comprises a burst of air or a solid object configured to travel within the hollow inner core region. 
     
     
       17. A method comprising:
 providing a first laser energy source and a second non-laser energy sources; 
 delivering a pattern of energy from the first source by scanning a surface of a solid material to create a moving pool of liquefied material which re-solidifies along a trailing edge, the energy from the first source delivered through an annular region of a multi-core fiber; and 
 repeatedly impacting the pool of liquefied material with pulses of non-laser energy from the second non-laser energy source to create a respective plurality of anchoring structures across the surface as the pool moves and the surface re-solidifies, the energy from the second source delivered within a hollow inner region of the multi-core fiber. 
 
     
     
       18. The method of  claim 17 , wherein the solid material is a bond coat of a thermal barrier coating system, and further comprising controlling the pattern of energy from the first energy source such that a depth of the moving pool is less than a thickness of the bond coat. 
     
     
       19. The method of  claim 17 , wherein the second non-laser energy sources is selected from one of mechanical, sonic, and ultrasonic energy sources. 
     
     
       20. The method of  claim 19 , wherein the second non-laser energy source is mechanical and the pulses of non-laser energy comprises a burst of air or a solid object sized less than a diameter of the hollow inner region of the multi-core fiber.